西双版纳人工林可持续经营研究

通过测定与分析木材及其他产品的经济效益、林分结构与林分生物量、生物多样性、土壤肥力与理化指标、保土涵水固碳等生态效益 ,对从云南热区选择出的 3个造林树种 :西南桦、山桂花、高阿丁枫及引种的热带速生树种马尖相思所营造的 4种人工纯林和 2种混交林半个轮伐期 (10年左右 )的状况和发展趋势进行了综合评价。研究结果表明 :这 6种人工林虽然主林层种类单一 ,但利用热区的自然条件 ,可以培育成具有复杂多样的下木、灌木、草本层植物的复层人工林 ,生物多样性 10年左右已可恢复到相似立地条件下天然林的状况 ;土壤肥力及理化性质在造林后先降后升 ,现已稳定回复到造林前水平 ;生物量较小 ,但木材经济产量较天然林高得多 ,由于木材价格高或兼有副产品 ,人工林的经济效益也较同地类的天然林高得多 ;保土涵水固碳等方面已发挥出良好的生态效益 ,人工林小流域内未见地表径流 ;因此认为这 6种人工林已达到了生态与经济效益兼顾的可持续经营的目标。

Study of Sustainable Management of Plantations in Xishuangbanna

The development status and trends of the pure stands of Betula alnoides, Paramichelia baillonii, Altingia excelsa and Acacia mangium, and the mixed stands of Betula alnoides and Paramichelia baillonii, Betula alnoides and Altingia excelsa, around ten years old, were studied based on the examination on several indexes including economic benefit, stand structure, stand biomass, biodiversity, soil fertility, soil physical and chemical characteristics, and ecological benefits such as soil and water conservation and carbon fixation The research results implied the following aspects 1) In spite of the mono species of tree layer, with the natural advantages of hot areas, the complex and diversified undergrowth, shrub and herb species could grow and develop, the biodiversity of the stand could be similar to the natural forests at similar site conditions 2) The soil fertility, the indexes of physical and chemical characteristics decrease right after the establishment of the stand, then increased, up to around 10 years old, have recovered to the level before establishing plantations 3) The biomass of plantations were low, however the commercial production of timber was higher than that of natural forest, considering the economic value of high price of timber and other byproducts, the economic benefit of plantation was significantly higher than that of natural forests 4) The plantation also showed promising function of soil and water conservation, no surface run off was found within the small watershed of plantations Summarizing the research results, it was preliminarily concluded that this six kinds of plantations achieved the objectives of overall considering ecological and economic benefits, was sustainably managed